Biochemistry behind stress-induced modulations of plant growth promoting rhizobacteria

Biochemistry deals with how several metabolic pathways share their information through chemical, physical and biological means. In case of plants, the soil and soil residing microorganisms interact and help the plant to grow and develop as well as kill it. How these interactions take place helps to understand what kind of metabolite is involved. The basis of studying these biochemical interactions comes through metabolomics, proteomics, lipidomics, glycobiology and genomics. The complete understanding of the overall interactions taking place when a plant is undergoing stress will reveal the mechanisms of bio-molecular interactions with physical components involved. This will allow making shift towards plant's growth and vigour enabling productivity and ensuring food security. Among most of the known organisms to ensure plant health, the key ones are plant growth promoting rhizobacteria (PGPR). The current review focuses on how PGPRs interact with soil and plant and playing the beneficial role. The PGPRs not only modulate the plant by its own metabolites moreover, it accelerates the metabolic flow of various hormones present in plants and thus takes a lead on plant's metabolic system. The crucial information that PGPRs delivers to the plant makes the plant's survival possible in stress. However, the interaction is so complex that challenges remain like the genetic components along with their enzymatic and bio-molecular counterparts are not fully deciphered yet. The changing climatic conditions with an arising need for climate-resilient agriculture is dependent to a larger extent on PGPRs favouring the plants. Thereby, it becomes crucial to decipher the components involved. The current review also focuses on synergistic interactions of PGPRs and biotechnological innovations showing what progress in understanding the stress induced modulations of PGPRs to plants has been done by the scientific minds.